Polyarylene sulfides are high-performance polymers that may withstand high thermal, chemical, and mechanical stresses and are beneficially utilized in a wide variety of applications. Polyarylene sulfides are generally formed via polymerization of a dihaloaromatic monomer with an alkali metal sulfide or an alkali metal hydrosulfide in an organic amide solvent.
The formation of polyarylene sulfides includes several distinct stages including the formation of a low molecular weight prepolymer followed by a second polymerization stage in which the molecular weight of the prepolymer is increased to form the final product. The formation is generally carried out in a batch-wise formation process in a single reactor. As such, the complete cycle time is at least the sum of all stages of the process, which can be quite long. Moreover, in order to be economically feasible, large reactors are required that must meet the specifications for the most stringent conditions of the process, i.e., the materials, pressure and temperature specifications of the single large reactor must be capable of withstanding the most stringent stage of the process, even though other stages may not require such exacting specifications.
What is needed in the art is a method and system for formation of polyarylene sulfides that can reduce cycle time and operating costs. Such improvements can improve capital efficiency and decrease pay-back time for an industrial-scale plant.